mnet can't setup a peer when a proxy is in use.

The mnet code doesn't contain any checks for proxies. This is actually fairly easy to fix, as using curl through a proxy is used and (proven) in other places. It only requires the routine that scrapes the site title to use download_file_content() - which just works - and to modify the curl call that gets the SSO key to check for proxies - mainly by taking the code from the former function.